Field of the Invention
The present invention relates to an in-cell touch liquid crystal display (LCD) apparatus in which an auto probe test pattern is provided in a pad area.
Discussion of the Related Art
Instead of a mouse or a keyboard applied as an input device of a display apparatus or a keypad applied as an input device of a portable electronic device, a touch screen that enables a user to directly input information with a finger or a pen is applied to display apparatuses. Since all users can easily manipulate the touch screen, the application of the touch screen is being expanded.
A touch screen is applied to monitors such as navigations, industrial terminals, notebook computers, financial automation equipment, and game machines, portable terminals such as portable phones, MP3 players, PDAs, PMPs, PSPs, portable game machines, DMB receivers, and tablet personal computers (PCs), and home appliances such as refrigerators, microwave ovens, and washing machines.
Recently, in-cell touch LCD apparatuses where a touch electrode (a touch sensor) is built into a cell of a liquid crystal panel have been developed for reducing the thickness and manufacturing cost of a touch display apparatus where a touch screen (a touch panel) is integrated with an LCD apparatus. The in-cell touch LCD apparatuses use a common electrode, which is disposed on a thin film transistor (TFT) array substrate of a liquid crystal panel, as a touch sensor.
FIG. 1 is a diagram illustrating a related art in-cell touch LCD apparatus 1.
Referring to FIG. 1, the related art in-cell touch LCD apparatus 1 includes an active area 10, where an image is displayed, and a pad area 20 disposed outside the active area 10.
A drive integrated circuit (IC) is mounted in or bonded to the pad area 20, and a plurality of link lines 21 and a plurality of touch routing lines 22 are disposed in the pad area 20. Also, an auto probe test pattern 30 is disposed in the pad area 20.
After a TFT array substrate is manufactured, an auto probe test process is performed for detecting a line defect such as short circuit and/or the like of lines disposed on a substrate, a defect of a TFT, a pixel pattern defect, etc.
To this end, the auto probe test pattern 30 for an auto probe test is disposed in the pad area 20 of a liquid crystal panel. By using the auto probe test pattern 30, a data voltage is applied to a data line, and a common voltage is applied to a common electrode line, whereby it is determined whether a plurality of lines and a plurality of pixels are normally provided on the TFT array substrate is tested.
FIG. 2 is a diagram illustrating an auto probe test pattern of a related art in-cell touch LCD apparatus, and FIG. 3 is a diagram illustrating a related art auto probe test method for an LCD apparatus.
Referring to FIGS. 2 and 3, an auto probe test pattern 30 of the related art in-cell touch LCD apparatus includes a common enable signal line 31, a common voltage switching unit 32, a data switching unit 33, a data signal line 34a, a common voltage line 34b, a data jumping part 35a, a common voltage jumping part 35b, a common voltage output pin bonding part 36, a data output pin bonding part 37, a common voltage link line 38, and a data link line 39.
The auto probe test pattern 30 of the related art in-cell touch LCD has a structure where an enable signal for the common voltage switching unit 32 and the data switching unit 33 is applied through the common enable signal line 31.
That is, a common voltage enable signal is applied to the common voltage switching unit 32 through the common enable signal line 31, and the common enable signal line 31 is disposed in order for a data enable signal to be applied to the data switching unit 33. In this case, a high voltage of ±5 V is applied as a data voltage, and a low voltage of −1 V is applied as a common voltage.
Even when performing an auto probe test identically to actual image driving, a polarity of a data voltage is inverted. In this case, if the common voltage switching unit 32 and the data switching unit 33 share the common enable signal line 31, a coupling phenomenon occurs where a common voltage is shifted according to a data voltage when the data voltage is inverted.
Due to the coupling of the data voltage and the common voltage, a time is expended in recovering the common voltage to the original common voltage (for example, −1 V). Also, the common voltage charged into a pixel is shifted due to the coupling, and for this reason, dimming occurs in a horizontal direction of a touch block.
That is, in the related art in-cell touch LCD apparatus, if the common voltage switching unit 32 and the data switching unit 33 of the auto probe test pattern 30 share the common enable signal line 31, horizontal-direction dimming occurs, and for this reason, an auto probe test cannot be normally performed.
The auto probe test pattern and the auto probe test method disclosed in this Background section was already known to the inventors of the present invention before achieving the present invention or is technical information acquired in the process of achieving the present invention. Therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.